Capacitor charging system for electronic flash apparatus

Claim 2

Electronic flash apparatus comprising: flash tube means for producing a light flash; first capacitor means for providing electrical current to the flash tube means; second capacitor means for discharging during the light flash, the second capacitor means being recharged from the first capacitor means subsequent to the termination of the light flash; first capacitor charging means for charging the first capacitor means; and control means for sensing when the second capacitor means is being recharged and causing the first capacitor charging means to begin charging the first capacitor means.

Claim 3

The electronic flash apparatus of claim 1 wherein the first capacitor charging means includes third capacitor means and wherein the first capacitor charging means charges the first capacitor means when the voltage across the third capacitor means decreases to a predetermined minimum value.

Claim 4

The electronic flash apparatus of claim 2 wherein the control means discharges the third capacitor means to reduce the voltage across the third capacitor means to the predetermined minimum value.

Claim 5

The electronic flash apparatus of claim 3 and further comprising first and second diodes connected between the first capacitor charging means and the first capacitor means for allowing unidirection current flow from the first capacitor charging means to the first capacitor means.

Claim 6

The electronic flash apparatus of claim 4 wherein the control means is connected to discharge the third capacitor means through the first diode.

Claim 7

Electronic flash apparatus comprising: first and second terminals; flash tube means for providing a light flash; first capacitor means connected to the first and second terminals, the first capacitor means providing electrical current to the flash tube means; flash terminating means for terminating the light flash, the terminating means including second capacitor means which is discharged during termination of the light flash; first capacitor charging means connected to the first and second terminals for charging the first capacitor means; second capacitor charging means for charging the second capacitor means means; and control means for sensing when the second capacitor means is being charged and for causing the first capacitor charging means to begin charging the first capacitor means when the second capacitor means is being charged.

Claim 8

Electronic flash apparatus comprising: first and second terminals; flash tube means for providing a light flash; first capacitor means connected to the first and second terminals, the first capacitor means providing electrical current to the flash tube means; flash terminating means for terminating the light flash, the terminating means including second capacitor means which is discharged during termination of the light flash; first capacitor charging means connected to the first and second terminals for charging the first capacitor means; second capacitor charging means for charging the second capacitor means means; and control means for sensing when the second capacitor means is being charged and for causing the first capacitor charging means to begin charging the first capacitor means when the second capacitor means is being charged.

Claim 9

The electronic flash apparatus of claim 6 wherein the terminating means further includes switching means connected in series with the flash tube means and the first capacitor means and wherein the second capacitor means applies a reverse voltage to the switching means to open the switching means and terminate the light flash.

Claim 10

The electronic flash apparatus of claim 6 further comprising first and second diodes connected between the first terminal and the first capacitor means for allowing unidirectional current flow from the first capacitor charging means to the first capacitor means.

Claim 11

The electronic flash apparatus of claim 8 wherein the first capacitor charging means includes third capacitor means and wherein the first capacitor charging means charges the first capacitor means when the voltage on the third capacitor means is reduced to a predetermined value.

Claim 12

The electronic flash apparatus of claim 9 wherein the control means discharges the third capacitor means to reduce the voltage on the third capacitor means to the predetermined value when the second capacitor means is being charged.

Claim 13

The electronic flash apparatus of claim 10 wherein the control means is connected to the second terminal and to a point between the first and second diodes.

Claim 14

The electronic flash apparatus of claim 11 wherein the control means discharges the third capacitor means through a current path from the first terminal, through the first diode, through the control means, and to the second terminal means.

Claim 15

The electronic flash apparatus of claim 12 wherein the control means comprises transistor means having base, emitter, and collector electrodes, the collector and emitter electrodes forming a current path from the first terminal through the first diode to the second terminal, and the base electrode being connected to sense charging current to the second capacitor means and controlling the flow of current between the collector and emitter electrodes as a function of the charging current.

Claim 16

In electronic flash apparatus including first capacitor means, flash tube means for selectively discharging the first capacitor means to provide flashes of light, second capacitor means for discharging during the flashes of light, first capacitor charging means for supplying first charging current to the first capacitor means, and second capacitor charging means for supplying second charging current from the first capacitor means to the second capacitor means, the improvement comprising: control means for controlling the first capacitor charging means as a function of the second charging current.

Claim 17

In electronic flash apparatus including first capacitor means, flash tube means for selectively discharging the first capacitor means to provide flashes of light, second capacitor means for discharging during the flashes of light, first capacitor charging means for supplying first charging current to the first capacitor means, and second capacitor charging means for supplying second charging current from the first capacitor means to the second capacitor means, the improvement comprising: control means for controlling the first capacitor charging means as a function of the second charging current.

Claim 18

The invention of claim 14 wherein the control means causes the first capacitor charging means to commence producing the first charging current when the second capacitor means receives the second charging current.

Claim 19

The invention of claim 14 wherein the first capacitor charging means comprises a DC to DC converter oscillator powered by a battery.

Claim 20

Electronic flash apparatus comprising: first capacitor means; flash tube means for selectively discharging the first capacitor means to produce light flashes; first capacitor charging means for supplying first charging current to the first capacitor means; terminating means for terminating the light flash, the terminating means including switching means connected in series with the flash tube means and the first capacitor means; and control means for causing first capacitor charging means to supply first charging current to the first capacitor means each time the terminating means terminates a light flash regardless of the amount the first capacitor discharged during the light flash.

Claim 21

Electronic flash apparatus comprising: first capacitor means; flash tube means for selectively discharging the first capacitor means to produce light flashes; first capacitor charging means for supplying first charging current to the first capacitor means; terminating means for terminating the light flash, the terminating means including switching means connected in series with the flash tube means and the first capacitor means; and control means for causing first capacitor charging means to supply first charging current to the first capacitor means each time the terminating means terminates a light flash regardless of the amount the first capacitor discharged during the light flash.

Claim 22

Electronic flash apparatus comprising: first capacitor means; flash tube means for selectively discharging the first capacitor means to produce light flashes; first capacitor charging means for charging the first capacitor means; terminating means for terminating the light flash, the terminating means including flash termination switch means connected in series with the flash tube means for switching from a conductive to a non-conductive state to terminate the light flash; and control means for sensing a signal associated with the termination of a light flash and for causing the first capacitor charging means to commence charging the first capacitor means.

Claim 23

Electronic flash apparatus comprising: first capacitor means; flash tube means for selectively discharging the first capacitor means to produce light flashes; first capacitor charging means for charging the first capacitor means; terminating means for terminating the light flash, the terminating means including flash termination switch means connected in series with the flash tube means for switching from a conductive to a non-conductive state to terminate the light flash; and control means for sensing a signal associated with the termination of a light flash and for causing the first capacitor charging means to commence charging the first capacitor means.

Claim 24

The electronic flash apparatus of claim 18 wherein the control means senses a current supplied to a circuit element during or immediately after a light flash.

Claim 25

The electronic flash apparatus of claim 18 wherein the control means senses a voltage supplied to a circuit element during or immediately after a light flash.